1. Field of the Invention
This invention relates generally to a safety device, and more particularly, to a device having retro-reflective elements associated with an animal to reflect light emitted from a light source directly back substantially along the same path to the position of the light source to improve the illumination of the device and the visibility thereof at nighttime.
2. Description of the Prior Art
Heretofore, it is known to connect light reflecting material to persons and/or objects, such as signs, to render such persons or objects more visible at night when subjected to light from an external source. In such instances, the visibility of the person or object being viewed is determined by the amount and color of light illuminating the person or object and the quantity thereof being reflected from the person or object.
The term "reflection" as used herein means the process by which light bounces off a surface. The three basic types of reflection include diffuse reflection, mirror reflection and retro-reflection. In diffuse reflection, the light strikes a surface which is microscopically rough scattering the light in all directions. Because only a very small amount of light is returned along the path of the incident (incoming) light beam, diffuse reflecting materials have low nighttime visibility.
In mirror reflection, the light strikes a surface which is microscopically smooth reflecting the light from the surface to an equal, but opposite, angle from that of the incident light beam. In mirror reflection, light is returned directly to the source only when the light beam is exactly perpendicular to the surface. Accordingly, mirror-like reflecting materials also are not favored for improving nighttime visibility.
In retro-reflection, the incoming light is returned directly to the source and appears brightest to an observer located near the light source. Because of the ability to return a large portion of the reflected light directly to the source, retro-reflective materials are used extensively for pedestrian safety, traffic signs and hazardous markings.
One form of retro-reflector involves a spherical lens element; such as a glass bead. The incident light beam is refracted (bent) as it passes through the front surface of the bead, is reflected from the back surface thereof, passes back through the bead, again is refracted as it leaves the front surface of the bead and returns along a path directly to the light source. In some applications, the back surface of the bead is coated with a reflective substance. In practice, reflex refractive materials do not direct all light directly back to the source. Rather, the reflected light returns in a cone-shape, with the most intense reflection returning to the center of the light source. However, the cone is very small, with virtually all of the reflected light being within 3.degree. in the incident light ray.
Retro-reflective materials now come in a number of forms for a wide variety of applications. For example, there is reflective fabric for nighttime pedestrian visibility; reflective sheeting for traffic signs, license plates and hazard markings; reflective liquids for spray or brush applications to rough surfaces; and reflective tape and paint for road lane pavement striping.
The above applications have not been entirely satisfactory in the case of animals; and particularly when walking a pet such as a dog at night. For example, there are instances where the use of reflective fabric to be worn either by the animal or the person walking the animal does not provide adequate safeguards; such as in adverse weather conditions requiring over-garments which have the tendency to cover any such retro-reflective fabric. As a result, many persons walking dogs at nighttime still carry a flashlight to signal oncoming traffic of their presence.
Accordingly, an object of the present invention is to provide an improved safety device for the animal by incorporating retro-reflective material directly into an animal control member, such as a combined collar and leash, thereby to improve the visibility thereof at nighttime.